Closed
Description
Bug report
Bug summary
Plotting a series of bar charts from a Pandas dataframe works fine when align='edge' but fails when align='center' unless dataframe variables are set to .values.
Code for reproduction
The following code works fine:
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
df = pd.DataFrame({'year':[2014]*12 + [2015]*12 + [2016]*12,
'month': list(range(1,13))*3,
'percent': np.random.uniform(0.1,0.5,36)})
fig, axArr = plt.subplots(3,figsize = [8,10],sharex = True,sharey = True)
# Keep track of which year to plot, starting with first year in dataset.
currYear = df['year'].min()
# Step through each subplot
for ax in axArr:
# Plot the data
rects = ax.bar(df.loc[df['year'] == currYear,'month'],
df.loc[df['year'] == currYear,'percent'],
align = 'edge')
currYear = currYear + 1...but replacing align='center' causes error (KeyError: 0):
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
df = pd.DataFrame({'year':[2014]*12 + [2015]*12 + [2016]*12,
'month': list(range(1,13))*3,
'percent': np.random.uniform(0.1,0.5,36)})
fig, axArr = plt.subplots(3,figsize = [8,10],sharex = True,sharey = True)
# Keep track of which year to plot, starting with first year in dataset.
currYear = df['year'].min()
# Step through each subplot
for ax in axArr:
# Plot the data
rects = ax.bar(df.loc[df['year'] == currYear,'month'],
df.loc[df['year'] == currYear,'percent'],
align = 'center')
currYear = currYear + 1When align = 'center', the code can be made to work by setting the dataframe data to 'values':
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
df = pd.DataFrame({'year':[2014]*12 + [2015]*12 + [2016]*12,
'month': list(range(1,13))*3,
'percent': np.random.uniform(0.1,0.5,36)})
fig, axArr = plt.subplots(3,figsize = [8,10],sharex = True,sharey = True)
# Keep track of which year to plot, starting with first year in dataset.
currYear = df['year'].min()
# Step through each subplot
for ax in axArr:
# Plot the data
rects = ax.bar(df.loc[df['year'] == currYear,'month'].values,
df.loc[df['year'] == currYear,'percent'].values,
align = 'center')
currYear = currYear + 1Actual outcome
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
<ipython-input-39-a3ac948488e0> in <module>()
18 rects = ax.bar(df.loc[df['year'] == currYear,'month'],
19 df.loc[df['year'] == currYear,'percent'],
---> 20 align = 'center')
21
22 currYear = currYear + 1
/Users/philjones/Documents/python_projects/python34_example_environment_2015-10-30/env3/lib/python3.4/site-packages/matplotlib/__init__.py in inner(ax, *args, **kwargs)
1896 warnings.warn(msg % (label_namer, func.__name__),
1897 RuntimeWarning, stacklevel=2)
-> 1898 return func(ax, *args, **kwargs)
1899 pre_doc = inner.__doc__
1900 if pre_doc is None:
/Users/philjones/Documents/python_projects/python34_example_environment_2015-10-30/env3/lib/python3.4/site-packages/matplotlib/axes/_axes.py in bar(self, left, height, width, bottom, **kwargs)
2103 if align == 'center':
2104 if orientation == 'vertical':
-> 2105 left = [left[i] - width[i] / 2. for i in xrange(len(left))]
2106 elif orientation == 'horizontal':
2107 bottom = [bottom[i] - height[i] / 2.
/Users/philjones/Documents/python_projects/python34_example_environment_2015-10-30/env3/lib/python3.4/site-packages/matplotlib/axes/_axes.py in <listcomp>(.0)
2103 if align == 'center':
2104 if orientation == 'vertical':
-> 2105 left = [left[i] - width[i] / 2. for i in xrange(len(left))]
2106 elif orientation == 'horizontal':
2107 bottom = [bottom[i] - height[i] / 2.
/Users/philjones/Documents/python_projects/python34_example_environment_2015-10-30/env3/lib/python3.4/site-packages/pandas/core/series.py in __getitem__(self, key)
601 key = com._apply_if_callable(key, self)
602 try:
--> 603 result = self.index.get_value(self, key)
604
605 if not is_scalar(result):
/Users/philj
5F8C
ones/Documents/python_projects/python34_example_environment_2015-10-30/env3/lib/python3.4/site-packages/pandas/indexes/base.py in get_value(self, series, key)
2167 try:
2168 return self._engine.get_value(s, k,
-> 2169 tz=getattr(series.dtype, 'tz', None))
2170 except KeyError as e1:
2171 if len(self) > 0 and self.inferred_type in ['integer', 'boolean']:
pandas/index.pyx in pandas.index.IndexEngine.get_value (pandas/index.c:3323)()
pandas/index.pyx in pandas.index.IndexEngine.get_value (pandas/index.c:3026)()
pandas/index.pyx in pandas.index.IndexEngine.get_loc (pandas/index.c:4009)()
pandas/src/hashtable_class_helper.pxi in pandas.hashtable.Int64HashTable.get_item (pandas/hashtable.c:8146)()
pandas/src/hashtable_class_helper.pxi in pandas.hashtable.Int64HashTable.get_item (pandas/hashtable.c:8090)()
KeyError: 0
Expected outcome
Expected output is a series of 3 bar charts, 1 per year represented in the dataframe, stacked one above the other.
Code used to work on Matplotlib 1.4.3 (except there were issues with spacing of y axis tick labels).
Matplotlib version
- Operating System: MacOS 10.11.6
- Matplotlib Version: 2.0.2
- Python Version: 3.4.1
- Jupyter Version (if applicable): 1.0.0
- Other Libraries: Numpy v1.13.0; Pandas 0.19.2
All libraries installed using pip.